Flacco is more statue-esque, yes. But don't let a couple designed runs and some work when play structure breaks down trick you into believing that either Flacco or Watson aren't drop back passers who work their eyes and arms first.
Passers with mobility have been across the NFL for a long time. Steve Young, McNair, Mcnabb, Ben, Luck, Burrow, Mahomes, etc etc.
It isn't just that they are safer, you're limiting potential non-contact injuries. People forget that RG3 knees were aggravated by his lateral cutting ability as much as they were some of the shots they took.
In fairness to Orion, your examples above don't work because two of them played behind the worst Olines in the NFL the last 25 years.